Automatic car-brake



(Nq Model.) 2 sheets-'sheet 1.

n T; BQ'THGMPSON,

Automatic Oar Bra-ke. No..237,14"3 y Patented Feb.1,1881.-

. NPEIRS, PmUTHOGRAPHE-R, WASHINGTON. DC

(No Model.)V

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N.PETERS. PHOTO-UTHOGRAFHEH. WSHINGTON D. C.

UNITED STATES PATENT OEEICE.

THOMAS E. THOMPSON, OF HYDE PARK, ASSIGNOR TO THE THOMPSON AUTOMATICTRAIN BRAKE COMPANY, OF CHICAGO, ILLINOIS.

AUTOMATIC CAR-BRAKE.

SPECIFICATION forming part of Letters Patent No. 237,143, dated February1, 1881.

Application tiled July 1, 1880.

To all whom it may concern:

Be it known that I, THOMAS E. THOMPSON, of Hyde Park, in thecounty ofCook and State of Illinois, have invented certain new and usefulImprovements in Automatic Train-Brakes and I declare that the followingis a full, clear, and exact description of the same, reference being hadto the accompanying drawings, in which- Figure 1 is a plan view of acar-truck and part of platform having' my improvements. Fig. 2 is atransverse section of the same, taken on the line x t in Fig. l. Fig. 3is a vertical longitudinal section taken on the line y y in Fig. l. Fig.4t is a transverse section taken on the line z z in Fig. 1. Fig. 5 is adetailed side elevation, onfan enlarged scale, of the mechanism foradjusting the disconnecting de vice. Fig. 6 is a section of the same,taken on the line o 'u lin Fig. 5.

The same letters denotethe same parts in all the figures.

My in'vention relates to mechanism for operating the brakes of arailway-car automatically by the inward movement of the drawbar causedby the pressure of the preceding vehicle, audits outward movement causedby the elasticity of the spring usually attached to it when thatpressure is removed. -This use of the inward and Outward movement Of thedraw-bar has been tried and found impracticable, on account of itsoperating to tighten the brakes whenever an attempt is made to back thetrain. l

The objectof my invention is to obvia-te this difficulty withoutimpairin g the operation under other circumstances.

My invention consists in utilizing the friction of the wheels on thebrake-shoes for this purpose, and it also consists in the severaldevices and combinations of devices which I will proceed to describeparticularly.

In the drawings, Arepresents a brake-wheel, with its shaft a, toothedwheel a', and pawl a2, chain a3, rod B, lever B', and rod B2, connectingthe lever B' with the brake-bars C and C', all of ordinary construction.

`The draw-bar D'hasthe usual spring d attached, bythe compression ofwhich, under 5o `the impact oftheadjoining vehicle, an inward (Nomodel.)

motion is given to it, usually of two inches, more or less, the springthrowing it out again when the pressure is sufficient] y relaxed. Withthe inner end of the draw-bar is connected a nearly-horizontaltoggle-joint, E, consisting of the two arms e and e2, hinged together ate. The end of e2 farthest from the hinge connects with an upright lever,F, pivoted at f on a fixed fulcrum. This lever is pivoted, at its lowerend, f', to one end of the rod Gr, the farther end of which is bent inthe form ot a loop, so as to clasp the lever B above its fulcrum b,which is affixed to the brakebar C', so that when the draw-bar is pushedinward the brakes will be applied in the same manner as by means ot' thehand-wheel. The two arms e and c2 of the toggle-joint slope veryslightly downward toward the knee, so that the latter is a little belowa horizontal line, connecting their farther ends, the length of each armbeing ordinarily about six inches. The knee is prevented, by the stopse3 on the upper sides of the adjoining ends of e and ez, from moving anyfarther in that direction. The tendency of the pressure on their ends istherefore to hold them rigid, and not in any degree to throw them abovea horizontal line. The arm e of the togglefjoint has projecting from itslower side, near the knee, a spur or cam, e, capable of engaging with atrip-cam, H, set on a shaft, h, which passes horizontally under E atright angles to its length and a little behind e4, and which issupported at either end in rests h and h2, attached to the inner sidesof a pair of timbers and opening into sockets set in those timbers. Asshown in the drawings, this cam is a rotating wheel. The shaft isslightly shorter than the distance between\the timbers, and may have alon gitudinal motion, limited by the depth of the sockets, so as tobring the trip-ca'm directly under E in a line to engage with the spure4, or a little to one side or the other, so as not to IOO so as to forma vertical arm, i, the lower end of which rests loosclyin a socket inthe upper surface and near the corresponding end of h. At its other end,near the rear end ot' the truck, the rod is bent sidewise at a rightangle, and then again into a direction parallel to the length of itsmain portion, so as to forni a sort of crank, i', the end of which restsin a slot, k, in the transverse lever K. This lever reaches froln oneside to the middle ot' the car, and is hinged at k' to a correspondingbut somewhat shorter lever, K. Each lever is pivoted at k2 and 7:3,respectively, 0n a fulcrum affixed to one of the timbers, so as to haveconsiderably the longer arm between the fnlcrum and the common joint,the crank i" engaging with K near k. The lever K extends no farther thanto a point above the end ot' the brake-bar C', with which it isconnected by a Vertical rod or hanger, I. The other lever, K, is, inlike manner, connected, by a hanger, I, with the other end of thebrake-bar, but eX- tends t0 the side of the car, where its end has anupward and downward motion in a guide, M, which is set on the inner sideof the outermost beam. The extent of this motion islimited by a guard orstop, N, which is parallel to the guide and is eccentricall y pivoted onthe Same side of the timber, at u, and which consists of a plate, u',through which the pivot passes, connected on one side with a rim orframe which surrounds the end of the lever K.

As shown in the drawings, N is in form somewhatlike a semicircle, havingits pivoted point near the straight side which corresponds to thediameter and its plate n adjoining that side, the pivoted point heilignearer to one end ofthe straight side than to the other.

The levers K and K are hinged in a ball, which is made of a weight notquite sutiicient to balance the tendency of the brake-bar C', to drawdown, by its weight, the outer ends ot' the levers, and thus force upthe jointed ends. The weight at k moderates this tendency, so that theouter ends of the levers will be drawn down, but not with that violencewhich would otherwise characterize the lnotion.

The upward motion of the inner end of K, caused by the downward motionof its outer end, necessarily raises the end ofthe crank t', and thusimparts a rocking inotiou to the rod I and its vertical arm i', whichmotion, in the particular arrangement of parts shown in the drawings,will be for all the radii below a horizontal line, and so forces the armi to the left. This motion, if not arrested, will bring the left end ofthe shaft h into the socketat h2, and thus put the trip-cam H clear tothe left of the toggle-joint E, so that it cannot engage with the spure4. 1f we suppose the shaft h to be as far as possible to the right atthe beginning of this motion, so that the tripcam will be on the rightof the toggle-joint, it is evident that at a certain point in thedownward motion of the outer end of K the trip-cam will be directlyunder the togglejoint, so that if, at that moment, the impact of thepreceding vehicle should force the drawbar far enough in, the spur e4would engage with the wheel and the knee of the toggle joint be thrownup above a horizontal line, thus crippling the connection between thedraw-bar and the brakes, so that the latter would be thenceforthentirely unaffected by the inward motion of the former. Now, the guard Nis so proportioned that when its shorter radius or the shorter arm ofitsstraight side is perpendicular below the pivot n, the corner orconcavity n2 of the rim will hold the outer end of the lever K atexactly' the requisite height to hold the trip-cam directly under thetoggle-joint E, so that without the application of some additional forcethe drawfbar will not operate the brakes. That additional force I tnd inthe friction of the brake-shoes against the wheels. When the car movesforward the hinder semi-circumference of each wheel has evidently anupward motion, which motion, in the case of the rear wheels of thetruck, will be communicated to the brakeshoes with great force when thelatter are pressed against them, even though the press ure be far fromsuiicient to stop the train. Now, the shaft h passes under thetoggle-joint E so far back of the spur e4 that, before c4 can come farenough back to engage with the tripcam, the drawbar must have beenpushed far enough in to bring the brake-shoes against the rear wheelswith pressure not suticient to stop the car, but abundantly sufficientto throw up the brake-shoes and the brake-bar C with great force. Thisupward motion is communicated, by the hanger l, to the lever K,

t the length of the shorter radius of N being snfiicient to allow theouter end ot'K to move so far up before striking the pivot n that, bythe downward movement of the inner end, the crank i will, in theparticular arrangement shown in the drawings, be turned downward and tothe right, imparting the same motion tothe rod I and its vertical armz', and thus pushing the shaft 11 so far to the right that the trip-caniwill be clear to the right of the toggle-joint E, and the connection ofthe drawbar with the brakes unimpaired. It is evident, then, that whenthe train is moving forward, the guard N heilig set in the positiondescribed, any pressure on the draw-bar caused by a slackening ofthespeed of the preceding vehicle will operate first to put the trip-camout of the way ofthe toggle-joint, and next to tighten the brakessufficiently to stop the car. 1f, now, it be attempted to back thetrain, the motion ofthe hinder semi-circumference of each wheel willevidently be downward instead of upward, and when, by the backwardmotion ot' the next preceding vehicle and the consequent pushing in ofthe drawbar and incipient tightening of the brakeshocs this motion iscommunicated to the brake-bar C', instead of pushing up the outer end ofthe lever K it will draw it down into IOO IIO

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the corner or concavity 7a2-that is, exactly into j the position whereit will operate 'to hold the trip-cam directlyunder the to ggle-jointE-and so cripple the connection ofthe draw-bar with the brakes whilethe pressure on the latter is still slight. In this way, it will beseen, I contrive to use the inward pressure of the drawbar to put on thebrakes automatically, for the purpose of arresting the forward motion ofthe train, while preventing that pressure from interfering in any degreewith backing the train.

When it is desired to reverse the principal motion of the car, so thatthe end which I have thus far called the front7 will become the rear,the mechanism which I have described will serve the same purpose, withthe addition of the lever P, which is pivoted at p on the inner side ot'the same tilnber to which the guard N is affixed a little in front ofN-that is, toward the toggle-joint. This lever is so pivoted that itsshorter arm p swings parallel to the guide N and so far tothe right ofit as just to clear it, except that a ange, q, projecting laterally fromthat portion of the curved periphery of N which isy opposite the shorterradius, engages the end of the lever when the shorter radius of N isbelow the pivot. When the car is to be used end for end in the way whichwe are now providing for the guide is to be reversed, so that its longerradius will be perpendicularly below the pivot n, as shown by dottedlines in Fig. 5 of the drawings. The flange q will then be above n, andthc arm p will be free to swing up in a plane parallel with N until itcomes in contactwith the lever K, just within the point where K wouldotherwise rest in the corner or concavityn3 of N. The longer arm p2 ofthe lever I is so ad- 4o justed as, by its superior length and weight,

in combination with the weight at lc', to overcome the tendency of theweight of the brakebar C with its brake-shoes to draw down the outer endof K, so that, unless some force additional to the weight of C opposes,the outer end of K will be held up as high as the guard N will permit.The construction of N is such that its central plate, n', through whichthe pivot n passes, is nearly all on the same side of 'n as the longerradius, so that the distance from the pivoted point to the farth er sidecfa is about equal to the distance from the other side of n to thecorner or concavity a2, or the point where the shorter arm of thestraight side touches the inner edge of the curved periphery, less thethickness or perpendicular dimension of the lever K, so that when thelonger radius of N is perpendicular below the pivot, K will be heldbetween the arm lo and the plate n at the same height as if it rested inthe corner n? formed by the curved periphery andthe shorter radius-thatis, at the requisite height to hold the trip-cam directly under thetoggle-j oint E- so that the connection of the draw-bar with the brakeswill be crippled before anything more than a slight pressure can betransmitted to the wheels. When the motion is backwardthat is, in thesame direction which in the former part of this specification is calledforwardL-there will be nothing to interfere with this operation of thelever I), the friction of' the wheels tending to force the brake-bar Cupward, and thus hold the outer end of K still more firmly in itsposition under the plate n', so that the operation of the draw-bar willnot interfere with the backing ot' the train. When, however, the motionis forwardthe same di rection called backward in the former part ot thespecicatiou-the downward momentum of t-he forward semi-circumferences ofthe wheels, communicated by friction to the brake-bar'G, will beabundantly suiicient' to overcome the weight ofthelougerarmpzofthe leverP, and to draw down the outer end of K until it rests in the corner orconcavityn3 formed by the junction of the longer radius of N with itscurved periphery, and thus to lift up the inner end of K far enough todraw the trip-cam H clear aside from the toggle-joint, so that theconnection of thedraw-bar with the brakes will remain unimpaired.

The position of N may be adjusted by means of a crank, N, formed bycontinuing the pivot n through the beam, and bending it on the outerside at a right angle. When adjusted it is held in position by the stopso, on one or the other of which the crank rests. The crank and guard areboth so set as to be on the side of their pivot toward the locomotivewhen in the right position.

The lever P might be dispensed with by using a spring attached at oneend to the lever K or K and at the other to one ot' the timbers, and soadjusted as, by its elasticity, to hold K in the right position to keepthe tripcam under the toggle-joint; but I iind the lever preferable inpractice.

The hangers l and l are so attached to the brake-bar and to thclevers Kand K', by hooked ends catching in staples or ring-bolts on thebrake-bar and levers, respectively, as to allow of considerable lateralmotion, so as to accommodate themselves to the motion of the carinrounding curves and otherwise swaying from side to side, withoutdisturbing the perpendicularity of their push and pull on the levers Kand K, and thus impairing the accuracy of operation of the devices whichI have described.

What I claim as my invention, and desire to secure by Letters Patent, is

1. In a system of car-brakes operated by the inward pressure of thedraw-bar, a brakebar receiving an upward or downward impulse from `itsfriction against the wheels, in combination with mechanism operated bythis impulse to control the mechanism for applying the brakes, wherebythe inward reciprocation of the draw-bar is made effective to apply' thebrakes in a retarded forward movement of the car,but ineffective in anybackward movement thereof.

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2. In asystem of carbrakes operated by the inward pressure of the draw-bar, a toggle-joint in the chain of mechanism between the drawbarand the brake-har, so adjusted as to be held rigid by that pressure, incombination with mechanism for automatically tripping it, substantiallyas and for the purpose described 3. 1n a system of carbrakes operated bypressure on the draw-bar, a toggle-joint inthe chain of mechanismbetween the draw-bar and the brakebar, so adjusted as to be held rigidby that pressure, in combination with mechanism for automaticallytripping it, aml with mechanism operated by the friction of the brakeson the wheels for regulating the con tact of the tripping mechanism withthe tog'- glejoint, substantially as and for the purpose described.

4. In a system of cai-brakes operated by pressure on the drawbar, atogglejoint between the drawbar and the brake-bar, so adjusted as to beheld rigid by that pressure, in combination with mechanism forautomatically tripping it, mechanism operated by the friction of thebrake-shoes on the wheels for regulating the contact of the trippingmechanism with the togglejoint, and a guard or stop to hold theregulating mechanism rigid against the force communicated from thefriction or leave it free to obey that force, substantially as and forthe purpose described.

5. ln a system ot' car-brakes operated by pressure on the draw-bar,mechanism for au tomatically crippling the connection of the draw-barwith the brakes, in combination with mechanism operated by the frictionof the brake-shoes on the wheels for regulating the crippling mechanism,and a guard capable of adjustment to liold the regulating mechanismimmovable against the impulse communicated by the friction or leave itfree to obey that impulse, substantially as and for the purposedescribed.

6. The draw-bar 1), toggle-joint E, with the spur e4, and mechanism forconnecting the toggle-joint with the brakes, trip-cam Il, shaft h, rodI, with its vertical arm i and crank end if, in combination withmechanism for operating the crank by the friction ot" the brake-shoes onthe Wheels, substantially as and for the purpose described.

7. The draw-bar D, toggle-joint E, with the spur e, and mechanism forconnecting the toggle-joint with the brakes, trip-cam H, shaft h, rod I,with its vertical arm i and crank end i', hinged levers K and K',connected with the brake-bar (1', so as to receive from it an upward ordownward impulse, eccentric guard N, with lever P and lia-nge q, all incombination, substantially as and for the purpose described.

8. The lever K, in combination with the 1ever K hinged thereto, thebrake-bar C', so connected with one of the arms oiK as to communicateits upward or downward impulse thereto, and mechanism for regulating theoperation of the brakes, said mechanism being connected with the. otherarm of K, all substantiall y as and for the purpose described.

9. The d raw-bar D, toggle-joint E, with the spur e4, and mechanism forconnecting the toggle-joint with the brakes, hinged levers K and K',with mechanism for automatically vibrating them, rod I, with its crankend 'i' and ver. tical arm t', shaft h, and trip-cam H, all incombination, substantially as and for the purpose described.

10. The eccentric guard N, having the plate n', on the same side ot' thecenter with the longer radius, in combination with the lever K,substantially as and for the purpose described.

1l. The eccentric guard N, in combination with the crank N and stops oand lever K, substantially as and for the purposes described.

12. The guard N, eccentrically pivoted, and provided with the plate n',on the same side of the pivotal joint as the larger portion of theguard, and with the iiange q, on the curved periphery of the smallerportion, in combination with the lever l and the lever K, allconstructed, arranged, and operating substantially as described.

THOMAS E. THOMPSON. Witnesses:

JN0. O. MACGREGOR, L. A. BUNTING.

